# Copyright (c) 2019, NVIDIA CORPORATION. All rights reserved.

# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at

#     http://www.apache.org/licenses/LICENSE-2.0

# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

from abc import abstractmethod

import torch


class Engine(object):
    r"""An ``Engine`` that runs the training/validation/inference process
    with the parameters specified.

    """

    def __init__(self):
        pass

    @abstractmethod
    def fit(self):
        raise NotImplementedError

    @abstractmethod
    def predict(self):
        raise NotImplementedError

    @abstractmethod
    def train_batch(self):
        raise NotImplementedError

    @abstractmethod
    def validate_batch(self):
        raise NotImplementedError

    @abstractmethod
    def optimize(self):
        raise NotImplementedError
